1. Field of the Invention
This invention relates to a novel process for growing crystals of high T.sub.c superconductors. More specifically, the invention pertains to a process for growing oriented crystals of high T.sub.c superconducting compounds greater than one millimeter in length.
2. Description of the Prior Art
Much has been reported regarding growing large crystals (i.e. crystals greater than one millimeter in length) of superconducting YBa.sub.2 Cu.sub.3 O.sub.7. Such growth of YBa.sub.2 Cu.sub.3 O.sub.7, as well as its rare earth counterparts, such as ErBa.sub.2 Cu.sub.3 O.sub.7, is difficult because of the compound's chemical reactivity, its peritectic decomposition, and the relatively high temperatures involved. It has been reported that good quality, millimeter sized crystals were grown using a liquid flux consisting of CuO and BaCuO.sub.2 in which the crystals grew from the liquid that had migrated out of the crucible onto a gold substrate support. D. L. Kaiser, F. Holtzberg, B. A. Scott, and T. R. McGuire, Appl. Phys. Lett. 51, 1040 (1987). However, while there are intense efforts to grow crystals of YBa.sub.2 Cu.sub.3 O.sub.7, little has been reported on the growth of the rare earth counterparts of this phase, such as ErBa.sub.2 Cu.sub.3 O.sub.7. This is because no one has succeeded in growing large, oriented crystals of the high T.sub.c rare earth superconducting materials.